[Python-Dev] troubling math bug under IRIX 6.5

[Tim Peters]

[Flying Cougar Burnette]
> ...
> >>> 4 * math.exp(-0.5)
> Bus error (core dumped)

Now let's look at the important <wink> part:

> (tommy@mace)/u0/tommy/pycvs/python/dist/src$ ./python
> Python 2.1a2 (#2, Feb 13 2001, 09:49:17) [C] on irix6
                                                  ^^^^^

The first thing to try on any SGI box is to recompile Python with
optimization turned off.  After that confirms it's the compiler's fault, we
can try to figure out where it's screwing up.  Do either of these blow up
too?

>>> 4 * 0.60653065971263342
>>> 4.0 * math.exp(-0.5)

Reason for asking:  "NV_MAGICCONST = 4 * _exp(-0.5)/_sqrt(2.0)" is the first
time random.py does either of a floating multiply or an int-to-float
conversion.

> is it just me?

Yup.  So long as you use SGI software, it always will be <wink>.

and-i-say-that-as-an-sgi-shareholder-ly y'rs  - tim